Concrete paving machines

ABSTRACT

A CONCRETE PAVING MACHINE COMPRISES A MAIN FRAME CARRYING A TRANSVERSELY-DISPOSED CONFORMING PLATE WHICH, AS THE MACHINE ADVANCES, LEVELS PLASTIC CONCRETE DELIVERED AHEAD OF THE MACHINE, SUB-FRAMES MOUNTED ON ENDLESS TRACKS AND UPON WHICH MAIN FRAME IS SUPPORTED WITH VERTICAL ADJUSTMENT AND, BETWEEN THE MAIN FRAME AND EACH SUB-FRAME A SYSTEM OF PARALLEL LINKAGE OPERABLE TO CONSTRAIN THE SUB-FRAME TO MOVE IN A VERTICAL PLANE RELATIVE TO THE MAIN FRAME.

Mchl3,1973 A.R IMMINGTON 20, 39

CONCRETE PAVING MACHINES Filed Sept. 5. 1970 2 Sheets-Sheet 1 March 13, 1973 VA. RIMMINGTON 3,720,439

CONCRETE PAVING MACHINES Filed Sept. 5, 1970 2 Sheets-Sheet 2 E 13 11 a 1 1 K 5 10 6 g r 1g I\1+ 6 INVENTOR ALAN RIMMINGTON By w NORRIS & BATEMAN United States Patent Oflice 3,720,439 CONCRETE PAVING MACHINES Alan Rimmington, Chesterfield, England, assignor to Robert McGregor & Sons Limited, Derbyshire, England Filed Sept. 3, 1970, Ser. No. 69,395 Claims priority, application Great Britain, Sept. 16, 1969, 45,615/69 Int. Cl. E01c 19/48 US. Cl. 296-48 4 Claims ABSTRACT OF THE DISCLOSURE A concrete paving machine comprises a main frame carrying a transversely-disposed conforming plate which, as the machine advances, levels plastic concrete delivered ahead of the machine, sub-frames mounted on endless tracks and upon which the main frame is supported with vertical adjustment and, between the main frame and each sub-frame a system of parallel linkage operable to constrain the sub-frame to move in a vertical plane relative to the main frame.

This invention relates to concrete paving machines as used in the construction of roads, paths, runways and similar surfaces.

The common form of paving machine at present in use comprises a main frame structure upon which is secured a conforming plate operable as the machine advances to level plastic concrete delivered onto the road or like subbase ahead of said plate. In such machines the main frame structure is usually supported on endless tracks and is vertically adjustable by means of jacks upon subframes carrying the endless tracks and their driving gear in order to vary the effective height of the conforming plate and thereby the depth of the laid concrete slab. Such machines will be referred to hereafter as machines of the kind mentioned." The machine is steered to follow a pre-set course with the aid of a probe carried on the machine and co-operating with pre-placed guide or control wires alongside the surface to be paved, but difficultly is often experienced in accurately following a desired course, the main reason for which has been the tendency of the tracks to move inward or outward relative to the machine frame, particularly on curves, and the resulting change of spacing can be significant to the extent that the horizontal alignment of the laid concrete slab suffers. The present invention provides an improved construction of machine which obviates this defect, at least to a very substantial extent, so permitting the machine to follow more accurately a pre-set or pre-determined course.

According to the invention there is interposed between the main frame structure and each subframe a restraining mechanism comprising a pair of vertically-spaced laterally-disposed arms or links operable in the manner of a parallel linkage to constrain the sub-frame to move in a vertical plane relative to the main frame structure.

A preferred embodiment of the invention will now be described with reference to the accompanying drawings wherein:

FIG. 1 is a fragmentary plan view of the improved paving machine, and

FIG. 2 is a side view of FIG. 1.

In the machine shown the main frame structure comprises two transversely-extending longitudinally-spaced tubular frame members 1 secured at their ends to vertical bracket structures 2 and at the front side of which is located a conforming plate 3, said plate in this instance being suspended at its ends on links 4 carried by the brackets 2 such that the conforming plate can swing transversely of the machine in the manner disclosed in the specification of US. Letters Patent No. 3,602,112 issued Aug.

3,720,439 Patented Mar. 13, 1973 31, 1971. The machine is supported on endless tracks 5, one at each side of the machine, these tracks being each mounted on a sub-frame 6 which carries the track driving gear 7 and which is carried on the lower end of a pair of jacks 8 adjustably mounted in a beam structure 9 secured to the brackets 2. Thus by raising or lowering the jacks the vertical position of the sub-frames 6 relative to the main frame 1 can be adjusted and thereby also the height of the conforming plate 3 above the ground.

For the purpose of the present invention there is provided at each side of the paving machine one or more sets of restraining linkage each set comprising two vertically-spaced swinging arms or links 10 which extend substantially laterally of the machine but converge slightly from their outer ends towards their inner ends. The arms are pivotally attached at their outer ends to the main frame structure and at their inner ends to two corners of a linking member in the form of a triangular-shaped plate 11 which, at its apex or third corner, has a pivotal connection 12 with the related sub-frame 6, the arrangement being such that any rising or falling movement of the sub-frame from its medial position and with corresponding tilting of the plate 11 rocks the arms 10 about their pivots in a manner such that the plate also moves outwardly to a degree sufficient to cause the apex thereof to move in a truly vertical path.

Preferably, the outer ends of the swinging arms 10 are pivoted on brackets 13 clamped or welded to the upper and lower sides of the tubular frame members 1. In the construction shown, two sets of restraining links are provided to each sub-frame, the two sets being longitudinally spaced on the machine and the pivots for the outer ends of their swinging arms consisting of longitudinally-extending spindles 14 common to the arms of both sets and to which the arms are secured whereby the two sets of linkage are caused to move in unison and so ensure a parallel vertical movement of the sub-frame.

Thus it will be seen that the provision of the restraining mechanism above described ensures an accurately controlled up and down movement of the sub-frames and endless tracks without any lateral deviation and thereby a more accurate following of a desired path or course.

I claim:

1. A concrete paving machine comprising a main frame structure, sub-frames at opposite sides of the main frame structure associated with ground engaging means, means whereby said sub-frames and said main frame structure are relatively vertically movable, and restraining mechanisms between the main frame structure and each subframe each comprising a pair of vertically spaced laterally extending arms pivoted to the main frame structure, a linking member to which said arms are pivotally connected at spaced locations, and means pivotally connecting said linking member to the adjacent sub-frame, each said pair of arms being pivotally mounted at one end on the main frame structure and converging laterally inwardly towards their other ends where they have pivotal connection at spaced points with said linking member which at a third laterally outwardly disposed point has pivotal connection with the sub-frame, said pivotal connections being so related that said mechanisms act to constrain each subframe to move only substantially vertically relative to the main frame structure.

2. A machine as claimed in claim 1, wherein two sets of restraining mechanism arms are provided to each subframe and are longitudinally spaced on the machine, the arms of the two sets being mounted on common pivots or spindles such that they are caused to move in unison.

3. A machine as claimed in claim 1 and in which the main frame structure of the machine comprises transverse tubular members, wherein the arms of the restrain- References Cited UNITED STATES PATENTS Hanson 9446 R Hanson 9446 R Hanson 9446 R Guntert 94-46 R X NILE C. BYERS, JR., Primary Examiner 

